Working as an undercover agent, Ransome Callicut travels west by stagecoach. Notorious bandit Vic Sutro tries to rob it, but Callicut captures him and turns over Sutro to an Army captain, Roy Giles, upon arrival in California.
School teacher Lora Roberts, another passenger, has made the trip to marry Giles, but she becomes ensnared in Senator Mark Sheldon's nefarious schemes and also discovers Giles has been seeing Chona Degnon, a singer.
The heart of the criminal operation is at the enormous nightclub/gambling house run by Buckley, where Chona is the headline entertainment. Attempting to win a rigged weight-lifting contest, Bryce's crony Olaf Swenson falls through the floor into the basement, where a large amount of illegal guns and gunpowder kegs are discovered.
The criminals are ostensibly attempting to make Southern California a slave state area. But this is only a blind for the true goal of cornering water rights and undiscovered oil land.
Sheldon murders a rival senator, Creegan, and fakes his own death. He kidnaps Lora as well. After she realizes that Callicut is actually a government agent, Lora persuades Chona that she can have Giles for herself if only she'll come to her aid. Sheldon also kills Chona before she can betray him, but he is brought to justice by Callicut, who is kissed by a grateful Lora.
